I had a shoulder dislocation, what now? – Part B

So in this second part of the topic I will go into further detail regarding the Bankart and Hill-Sachs injury. Also cover some of the main features of the clinical examination. First let us have a quick anatomy review (picture 1 & 2) from the last blog – I have a Shoulder Dislocation, what now – Part A, just to refresh your memory.

Picture 1

Picture 2

Bankart Lesion

A Bankart lesion is by definition an injury to anterior inferior labrum of the shoulder, as seen on the images below. I have discussed the role of the labrum and its clinical significance for shoulder stability on the previous blog. Please note that on the X-ray picture below, the red circle illustrates the ‘bony’ component of the bankart injury. In this case there is fracture to the inferior rim of the glenoid (socket of the shoulder), which is caused by the humeral head during traumatic dislocations.

Unfortunately, bankart injuries require surgical repair given that the torn labrum increases joint laxity leading to shoulder instability. There are different surgical techniques and procedures which will be chosen according to the needs of the patient and should be discussed on an individual basis. In summary, the main goal is to repair the injury and re-gain shoulder instability.

The Hill-Sachs injury is routinely found in traumatic anterior shoulder dislocations and can be associated or not with the Bankart Injury. By definition, a Hill-Sachs injury is a depression fracture of the posterolateral aspect of the humeral head, which happens as a consequence of the impact between the humeral head and the antero-inferior glenoid rim during the anterior dislocation of the shoulder.

Different from from Bankart injuries, it severity can vary and surgery is not always warranted. There is debate in the medical literature on best management options. Consequently, decisions are made on individual basis taking into consideration the size and type of injury. The main factor is recurrency of instability symptoms.

Ultimately, the flattening of the humeral head may affect the its articulation with the glenoid fossa. Consequently certain shoulder movements, particularly overhead, may expose the joint to instability and further dislocations. The other factor to be considered is that recurrent shoulder dislocations, even of non-traumatic mechanism, will always expose the joint to further injuries and soft tissue laxity, including capsule and surrounding ligaments. See the images below for your reference.

Clinical Evaluation

There are two very common tests used in day to day practice in order to diagnose anterior shoulder instability. Please note, dislocations can be easily diagnosed via patient interview and / or inspection before joint reduction. I remind the reader to not mistake the dislocation episode, which may lead to instability with atraumatic shoulder instability which can be present without any previous history of dislocation. They are two distinct entities where one can exist without the other.

The Load and Shift Test and the Anterior Apprehension test are quite easily executed by a skilled clinician.

The first consists on an attempt to glide the humeral head onto the glenoid fossa anteriorly and posteriorly. The joint laxity / movement is felt and compared to the contralateral side. Increased translation or the ability to migrate the humeral head anteriorly over its anatomical boundaries will constitute a positive test.

Load and Shift Test

The second, consists of the examiner elevating the arm of the patient to 90 degrees of abduction and passively adding external rotation to the glenohumeral joint. In that angle, as the arm is rotated backwards, the head of the humerus translates forward into the glenoid fossa and if instability symptoms are present the patient will show hesitation and stop the movement. In other instances such ‘hesitant behaviour’ is only witnessed when the client is asked to push against the examiner.

Such movement can be extremely distressful for someone who experiences anterior instability, notably if they have been exposed to traumatic shoulder dislocations. Also worth mentioning that some clients may present with ‘hesitant behaviour’ due to mental fear despite the absence of true instability. A good clinician will be able to assess and differentiate both.

Anterior Apprehension test

Imaging, particularly Magnetic Resonance Imaging (MRI) can be quite helpful in diagnosing injuries such as Hill Sachs and Bankart. The reliability of physical examination findings for those injuries is not the best and history and quality imaging are gold standards. However, when diagnosing anterior shoulder instability, there is evidence in the literature that good history-taking combined with the load and shift + apprehension tests are just as reliable as MRI. It is my opinion that for the latter, clinical findings are superior than imaging alone.

A more functional test that is also used in daily practice is the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST). Although not specific for anterior shoulder stability, this test has very good reliability and validity in assessing shoulder instability. It is used in sports context as a one of the benchmarks to determine readiness for participation and / or injury risk stratification. Its procedure is quite simple and consists on the individual assuming a push-up position with hands apart to obeying a specific distance. The individual is then instructed to shift his weight from side to side touching his right hand on the left hand and vice-versa in sequence. The ‘passing mark’ for males is 24 touches inside 15 seconds with good form.

I hope that provides you with a better overview about anterior shoulder dislocations, its management and assessment.